Advice on Planting Aquatic Plants

This is a discussion on Advice on Planting Aquatic Plants within the Beginner Planted Aquarium forums, part of the Beginner Freshwater Aquarium category; -->
Hi!
So, I want to plant live plants in my 5 gallon tank which is occupied by two fantail goldfish*, and want to plant ...

Hi!
So, I want to plant live plants in my 5 gallon tank which is occupied by two fantail goldfish*, and want to plant live plants. The tank doesn't have a heater, and the filter has a power of 5-10 gallons.
Any advice on...
1. What kind of plants I should plant?
2. How many I should plant?
3. How I should care for the plants?

*I know that 5 gallons is kind of small for two goldfish, but they've been living well for 3, nearly 4, years. And they are healthy.
Plus, fantails only grow as big as is appropriate for the tank they are living in.

5 gallons is way too small for two gold fish. The "fantails only grow as is appropriate for the tank they are living in" is a complete myth. Goldfish living in that small of a space will die way earlier than they are supposed to. Goldfish are extremely messy eaters and will produce much more ammonia than normal fish. 4 years is not much for goldfish, they can live up to 20 years old... One way to put this in perspective... Have you ever met anyone who has kept goldfish alive for more than 10 years (only half their possible lifespan) in a tank or bowl less than 10 gallons?

As for plants, plants will help the situation but relocating the goldfish is still necessary. Kind of plants is really of your preference. There are slow growing buried or rhibozome (did I spell that right?) plants. Fast growing plants tend to be stem or floating plants. Fast growing plants tend to help control water quality more. Other than that it is really personal preference. Make sure your water parameters are suitable for your plants. As for how many you should plant is also personal preference. More, however will help control water quality better. As for care, decide wether you want to go high or low tech. High tech means lots of light and plant fertilizer. Low tech is less light and little to no fertilizer.

Thank you!
About the Goldfish myth...maybe it is a myth, I don't know, but it's either the tank seems smaller or my fish have grown since they've been in the new tank. :)
I had a common goldfish who lived all my himself in a 5 gallon tank for about 5 years, not 10 years I know but kind of similar as I was not really as experienced at that time. And considering he was also from Walmart.

I think from what you said I want a type of stem plant. And probably I'll go low tech.

I was going to metion the stunting that aokashi mentioned but I wasn't sure if it had been confirmed yet. I do certainly know that 5 gallons is far too small for goldfish.

There is also another factor I didn't mention (again I am pretty sure this is not confirmed). The theory is that fish can sense when the envirement is too small, so they stop growning. However, if this is true than the stunting thing is also definitely true.

No fish can grow to the size of their aquarium. They are no different from any animal or human in that regard. I could, theoretically, place an infant child in a 2ft square cage. At the beginning, more than enough room.

Eventually that kid is going to grow as much as it can in that space, and when there is no more room to grow 'normally' their body will twist and stunt as it keeps trying to grow.

For goldfish (especially fantails, who already have deformed bodies to begin with) this also means that theur internal organs will keep growing until they rupture or compact another organ. Especially with the heart and digestive system.

I'm sorry but I can't in good conscience give you advice for plants until you find more suitable accommodations for your fish.

Also, goldfish are herbivores and will eat any stem plant placed in your tank.

Okay, I know that the fish would eat the plants. :) But its not like they would finish off the whole thing the first day the plants were in the tank, and if the plants are consumed and don't do anything bad to the fish, I think its a good thing. :)